Numerical simulation results with AUTODYN software revealed Jing Ping Lu′s parameters of PBXW-115 ignition and growth model underestimate energy release of Al powders combustion. The effects of artificial viscosity coefficient and mesh density on simulation results were discussed. The larger artificial viscosity coefficients and coarser meshes can smear off peak pressure of shock wave severely,but affect impulse little. Based on Bocksterner′s underwater explosion experimental results,parameters of Miller energy release model were solved inversely. Weighted coefficient of impulse was twice as much as that of peak pressure in objective function. New model parameters obtained from underwater explosion test can express the size effect of aluminized explosive and can be applied to numerican simulation of near field and far field, while Lee-Trave model parameters can only be applied to the numerical simulation of near field and small yield underwater explosion.